Positioning apparatus, exposure apparatus using thereof and device manufacturing method

ABSTRACT

A positioning apparatus including a movable member having a plurality of magnets, and a plurality of coils arranged in X- and Y-axial directions, for displacing the movable member in the X- and Y-axial directions, and in a rotational direction around the Z-axis.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No. 11/264,881, filed Nov. 1, 2005, which claims the benefit of Japanese Patent Laid-Open No. 2004-323759, filed Nov. 8, 2004, which are hereby incorporated by reference herein in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a positioning apparatus, and in particular, though not exclusively, to a positioning apparatus used in an exposure apparatus and/or survey equipment.

2. Description of the Related Art

A conventional exposure apparatus can have a positioning apparatus for positioning a wafer or a reticle. Japanese Patent Laid-Open No. 2004-254489 discusses a stage unit using a surface motor, as a wafer stage, for positioning a wafer.

FIG. 8A illustrates a top view which shows the wafer stage 8 discussed in Japanese Patent Laid-Open No. 2004-254489, and FIG. 8B illustrates a sectional view which shows the wafer stage 8 as viewed sidewise.

Referring to these figures, a movable member 1 (stage) includes a magnet unit 2 in which permanent magnets are arranged in the so-called Halbach array at its bottom surface, and a base member 3, which has a coil unit 4 in which a plurality of coils are arranged. Magnetic fluxes generated from these permanent magnets and currents fed to the coils produce a Lorentz's force by which the movable member 1 is displaced.

FIGS. 9A to 9B illustrate views which show a configuration of coils and permanent magnets discussed in the Japanese Patent Laid-Open No. 2004-254489, as viewed from above in FIGS. 8A and 8B, and in which the stage is shown being see-through in order to facilitate the understanding of the configuration thereof. A plurality of coils 5 having linear portions in the X-axial direction are arranged in the Y-axial direction, and current having predetermined phases are fed to those of the coils 5 which are located underneath the magnets so as to displace the stage in the Y-axial direction. Further, with the provision of a plurality of coils having linear portions in the Y-axial direction, which are arranged in the X-axial direction, the stage can be displaced in the X-axial direction. It is noted here that the magnet unit 2 has such a magnetic configuration that the Halbach array has deficient parts 6 from which permanent magnets are in part removed as shown in FIG. 9A, or the Halbach array has additional parts in which permanent magnets are in part added 7 as shown in FIG. 9B. With this magnet configuration, currents are fed to coils underneath a pair of deficient parts 6 or additional parts 7 so as to induce forces in reverse direction, respectively therefrom, so as to cause the stage 1 to displace in the θz direction (a rotational direction around the Z-axis).

As illustrated in FIG. 9A, if defective portions are provided in permanent magnets having an array sequence, permanent magnets used for X- and Y-axial displacements can be removed, resulting in decreased drive efficiency. As illustrated in FIG. 9B, if additional portions are provided in permanent magnets having an array sequence, separates coils for θz drive can be used in addition to coils for X- and Y-axial drives in order to increase efficiency of the drive. In this case, since a current applied for the θz drive is different from currents applied for the X- or Y-axial drive, different current drives can be used, that is, an increase in the number of current drivers results in increased costs. Further, since the additional magnets overhang outward by a large degree, the stage itself would have a larger size, the larger the carriage, the larger the apparatus and as well the larger the heating value of a drive unit, resulting in difficulty in maintaining increased accuracy.

SUMMARY OF THE INVENTION

At least one exemplary embodiment is directed to a positioning apparatus for positioning an original to be exposed, a matter to be exposed, or positioning a test object to a predetermined position.

At least one exemplary embodiment is directed to a positioning apparatus including a movable member having a plurality of magnets, a plurality of coils arranged in X- and Y-axial directions, for displacing the movable member in these directions. The plurality of magnets constitute a first magnet unit for generating forces in X- and Y-axial directions, and a second magnet unit for generating a force in a direction around the Z-axis. The second magnetic unit being provided so as to cause at least a part of coils for generating a force in the X-axial direction to generate a force in a rotating direction around the Z-axis, while reducing generation of a force in the Y-axial direction. Incidentally, the X- and Y-axial directions can be used for defining two orthogonal directions in one and the same plane, are synonymous with a first direction and a second direction orthogonal the first direction.

Further, the second magnet unit can include a plurality of magnets which, in at least one exemplary embodiment, are configured so that N-poles and S-poles are alternately arranged in the X-axial direction. The first magnetic unit can include a plurality of magnets, where in at least one exemplary embodiment are configured so that N-poles and S-poles are alternately arranged in X- and Y-axial directions. It is noted here that “the plurality of magnets configured so that N-poles and S-poles are alternately arranged”, are those which are located so that the polarities of N-poles and S-poles are alternately opposed to coil units.

At least one further exemplary embodiment is directed to a positioning apparatus for displacing a movable member with the use of magnets and coils, at least two dimensionally, which is movable in a rotational direction while (1) increasing the drive efficiency, and/or (2) decreasing of the size of the movable member and/or (3) decreasing the cost.

Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plane view illustrating a magnet configuration of a surface motor type wafer stage in accordance with at least one exemplary embodiment;

FIG. 2 is a plane view illustrating a positional relationship between a magnetic unit and a coil unit during movement in an X-axial direction;

FIG. 3 is a plane view illustrating a positional relationship between a magnetic unit and a coil unit during movement in a θz direction;

FIG. 4 is a plane view illustrating a positional relationship between a magnetic unit and a coil unit during movement in a Y-axial direction;

FIG. 5 is a side view illustrating an exposure device;

FIG. 6 illustrates a view for explaining a device manufacturing method;

FIG. 7 illustrates a view for explaining a wafer process;

FIG. 8A is a top view illustrating a surface motor type wafer stage;

FIG. 8B is a sectional view illustrating the surface motor type wafer stage shown in FIG. 8A;

FIGS. 9A and 9B are views illustrating magnet configurations of conventional surface motor type wafer stages.

DESCRIPTION OF THE EMBODIMENTS

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

Processes, techniques, apparatus, and materials as known by one of ordinary skill in the art may not be discussed in detail but are intended to be part of the enabling description where appropriate. For example magnets are discussed and any material that can be used to form elements of the magnets should fall within the scope of exemplary embodiments (e.g., iron).

Additionally the actual size of the elements of exemplary embodiments may not be discussed, however any size from macro to micro and nano are intended to lie within the scope of exemplary embodiments (e.g., magnets with diameters of nanometer size, micro size, centimeter, and meter sizes). Additionally exemplary embodiments are not limited to moving wafer stages in exposure systems, for example the system can be designed for use in moving units between stages in a fabrication process.

Examples of several exemplary embodiments are described below with reference to the accompanying drawings.

Exemplary Embodiment 1

Referring to FIG. 8A which is a top view illustrating a stage unit in an exemplary embodiment 1 and FIG. 8B which is a sectional view illustrating the stage unit as viewed sidewise, a stage (movable member) 1 carrying thereon an object to be positioned, is movable in X- and Y-axial directions on a base member 3. The stage 1 has, at its bottom surface, a magnetic unit 2 which will be described later. The base member 3 has, at its surface opposing the magnetic unit 2, serving a platen as a whole. The coil unit 4 has a first coil layer in which a plurality of coils are arranged in an X-axial direction, each coil having a linear portion in a Y-axial direction so that its longitudinal direction is laid in the Y-axial direction. Underneath the first coil layer (downward in a minus Z-axial direction, into the page), there is a second coil layer in which a plurality of coils are arranged in Y-axial direction, each coil having a linear portion in the X-axial direction so that its longitudinal direction is laid in the X-axial direction. Further, in accordance with the exemplary embodiment, the coil unit 4 can include additional coil layers in which coils are arranged, each having a linear portion in a predetermined direction. The coils can be secured to the base member 3, and the coil unit 4 can be covered thereover with a jacket which is not shown. With this configuration, heat which is generated when current is fed to the coil can be cooled by feeding coolant through the jacket or by arranging cooling pipes among the coils, or by hollow coils where coolant flows through the center of the hollow coils.

FIG. 1 is a top view illustrating the stage as see-through in order to facilitate the understanding of the configuration of magnets arranged at the bottom surface of the stage. Magnets 21 in FIG. 1 are main-pole magnets which are magnetized in the Z-axial (perpendicular) direction, having N-poles on the −Z side (the bottom surface of the stage). Magnets 22 are main pole magnets 22 which are magnetized in the Z-axial direction, having S-poles in the −Z side. Magnets 23 are commutating pole magnets which are magnetized in a horizontal direction (e.g., along the X-Y plane), and are arranged so that poles at their ends are coincident with that of the main pole magnets adjacent thereto, as viewed from the bottom surface. That is, the so-called Halbach array is two-dimensionally formed in the X- and Y-axial directions. Note that exemplary embodiments are not limited to the magnets being arranged in a Halbach array. Such a discussion is meant for illustrative non limiting purposes.

Thus, in such a Halbach array, the magnets 22, 23 are symmetrically arranged in the X- and Y-axial directions so as to form a magnet unit 24 which is substantially square as a whole. Magnet units 25 a, 25 b are arranged on both sides of the magnet unit 24 as viewed in the X-axial direction, in the non-limiting example illustrated each includes four magnets which are arranged in a row so as that S-poles and N-pole are opposed to the coil unit 4, S-poles and N-pole being alternately set in the X-axial direction. Note any number besides four can be used in at least one exemplary embodiment. The magnet units 25 a and 25 b can be provided in pair, being spaced from each other by a distance L in the Y-axial direction, that is, the magnet unit 24 is interposed therebetween in the Y-axial direction.

Explanation will be made of a positional relationship between the magnet unit 2 and the coil unit 4. Referring to FIG. 2 in which the second coil layer is not shown but only the first coil layer is shown. Further, long length coils can be arranged in order to displace the stage in the X- and Y-axial directions by long strokes, the coils shown in FIG. 2 have a short-length in order to facilitate the explanation thereof. Further, the coils are shown by a number (e.g., CX1-CX17) which is less than the total number thereof in order to facilitate the explanation thereof.

Explanation will be hereinbelow made of a manner of displacing the stage in the X-axial direction with reference to FIG. 2.

The coils are arranged in the X-axial direction at pitches CP, and in the magnet unit 24 (FIG. 1), the magnets having one and the same poles are arranged in the X-axial direction at pitches MP. It is noted here that the pitches CP and MP can vary and in at least one exemplary embodiment satisfies the following equation;

MP=4/3*CP  (1)

Magnetic fluxes produced by the magnets in the coil unit 24 (FIG. 1) of the stage exhibit a magnetic flux density distribution having a predetermined period. If the magnets are in the Halbach array, an averaged value of the magnetic flux density distribution in the Z-axial direction at the position of the coil unit can be approximated to a sinusoidal wave substantially having a period MP with respect to the X-axis.

Referring to FIG. 2, when the stage located at an X-axial position x=0 is displaced in a range 0<x<CP, a thrust fi (i=2 to 15) which is induced in the X-axial direction from a coil cxi (i-th coil from the left side of the figure) fed thereto with a current Ii [A] is exhibited by the following functions:

f2, f6, f10, f14=−Ii*Ki*cos(2*π/MP*x)  (2)

f4, f8, f12=Ii*Ki*cos(2*π/MP*x)  (3)

f3, f7, f11, f15=Ii*Ki*sin(2*π/MP*x)  (4)

f5, f9, f13=−Ii*Ki*sin(2*π/MP*x)  (5)

where Ki is a constant. It is noted that the value Ki is slightly different for f4, f5, f12, f13 from those for the other thrusts induced by the other coils, these differences can be negligible (Ki≈K) in view of the control of macro movements.

Further, if a current Ii (i=2 to 15) is fed to a coil cxi (i-th coil from the left side in the figure) as follows:

I2, I6, I10, I14=−I*cos(2*π/MP*x)  (6)

I4, I8, I12=I*cos(2*π/MP*x)  (7)

I3, I7, I11, I15=I*sin(2*π/MP*x)  (8)

I5, I9, I13=−I*sin(2*π/MP*x)  (9)

a resultant force (f2+f3) is exhibited by:

$\begin{matrix} \begin{matrix} {\left( {{f\; 2} + {f\; 3}} \right) = {I*K*\cos^{\bigwedge}2\left( {{2*{\pi/{MP}}*x} +} \right.}} \\ {{I*K*\sin^{\bigwedge}2\left( {2*{\pi/{MP}}*x} \right)}} \\ {= {I*K}} \end{matrix} & (10) \end{matrix}$

Further, for every y resultant force (f4+f5), (f5+f7), (f8+f9), (f10+f11), (f12+f13) and (f14+f15), I*K can be similarly obtained, and accordingly, 7*I*K is obtained as the total resultant force. That is, whenever there is a desire to induce a force F, the current I can be set to:

I=F/7K  (11)

A laser interferometer which is not shown can be used in order to measure a position x of the stage. It should be noted here that the phase of the current Ii is set so as to be coincident with that of the magnetic density distribution. That is, a measured value obtained by the laser interferometer can be used as a feed-back signal for the position control of the stage, and used to compute a phase of the above-mentioned current.

A manner of displacing the stage in the Y-axial direction is carried out, similar to that for displacing the stage in the X-axial direction. That is, by measuring a position of the stage in the Y-axial direction, and predetermined currents are fed to coils in the second coil layer so as to induce a predetermined thrust in the Y-axial direction. Referring to FIG. 4 which shows only the second coil layer without the first coil layer. Further, several coils having a long length should be arranged in order to displace the stages in the X- and Y-axial directions by a long stroke, coils having a shorter length are shown by a number less than the number in FIG. 4 in order to facilitate the explanation thereof.

The coils (e.g., CY1-CY18) are arranged in the Y-axial direction at pitches CPY, and in the magnetic unit 24, the magnets having the one and the same pole are arranged in the Y-axial direction at pitches MP which are set as follows;

MPY=4/3*CPY  (1)

Magnetic fluxes generated by the magnets in the magnet unit 24 (FIG. 1) of the stage exhibit a magnetic flux density distribution having a predetermined period at the position of the coil unit. Since the magnets are arranged in a Halbach array, an averaged value of the magnetic flux density distribution in the Z-axial direction at the position of the coil unit, can be approximated to a sinusoidal wave substantially having a period MPY. It is note here that the Halbach array is two-dimensionally formed so as to cause difference in the magnetic flux density distribution among coil parts, and accordingly, “the averaged value of the magnetic flux density distribution” is used.

A manner of displacing the stage in the Z-axial direction is similar as mentioned above, except that a phase of current fed to each coil is different from that for the displacement in the X- and Y-axial direction by 90 deg. By shifting the phase by 90 deg. a Z-axial thrust can be induced between the magnetic unit at the bottom surface of the stage and the first coil layer or the second coil layer.

In order to displace the stage in the Z-axial direction with the first coil layer, a certain number of coils can be chosen, for example twelve (12) coils cx3 to cx14. In the case of using 12 coils, the current value I for inducing a thrust F can be set to a value obtained by multiplying (F/Kz/6) with a phase of each coil, where Kz is a coefficient.

Explanation will be hereinbelow made of displacement of the stage in a θx direction (rotational direction around the X-axis) or a θy direction (rotational direction around the Y-axis).

Referring to FIG. 2, a thrust in the −Z-axial direction is induced with the use of the coils in the stage on the left side (−X side) of the center line A while a thrust in the +Z-axial direction is induced with the use of the coils in the stage on the right side (+X side) of the center line A, and accordingly, a thrust in the θy direction can be induced in the stage.

Similarly (FIG. 4), a thrust in the +Z-axial direction can be induced with the use of the cols in the stage on the upper side (+Y side) of the center line B while a thrust in the −Z-axial direction can be induced with the use of the coils in the stage on the lower side (−Y side) of the center line B, and accordingly, a thrust in the θx direction can be induced in the stage.

The positions of the stage in the θx and θy directions can be measured by providing two optical axes of laser interferometers for measuring positions respectively in the Y- and X-axial directions, which are spaced in the Z-axial direction. Specifically, it can be obtained by dividing a difference between measured values along the two optical axes with the space between two optical axes in the Z-axial direction.

As stated above, in order to induce thrusts in the X-, Y- and Z-axial directions, and in the θx and θy directions, the magnet unit 24 (FIG. 1) in which the magnets are arranged in the Halbach array is used. It is noted that the magnets are tightly laid in the magnet unit in a square shape in order to enhance the thrust efficiency, although any shape is in accordance with exemplary embodiments.

Next, explanation will be made of a manner of displacing the stage in a θz direction with reference to FIG. 3. In order to induce a thrust in the θz direction in the stage, coils cx4, cx5, cx12 and cx13 located underneath the magnetic units 25 a, 25 b are used.

When current I′i [A] is fed to each coil, thrusts f′4, f′5, f′12, f′13 in the X-axial direction are exhibited as follows:

f′4, f′12=I′i*K′*cos(2*π/MP*x)  (12)

f′5, f′13=−I′i*K′*sin(2*π/MP*x)  (13)

where K′ is a constant and the differences between K′ values between coils is deemed negligible. Further, currents I′4, I′5, I′12, I′13 fed to the coils (cx4, cx5, cx12 and cx13) are set as follows:

I′4=I*cos(2*π/MP*x)  (14)

I′5=−I*sin(2*π/MP*x)  (15)

I′12=−I*cos(2*π/MP*x)  (16)

I′13=I*sin(2*π/MP*x)  (17)

That is, if the current values fed to the coils cx12, cx13 are set to values obtained by multiplying the current values fed to the coils cx4, cx4 with −I, resultant force (f′4+f′5) and (f12+f13) are exhibited as follows:

f′4+f′5=I′*K′*cos ̂2(2*π/MP*x)+I′*K′*sin ̂2(2*π/MP*x)=I′*K′  (18)

f′12+f′13=−I′*( K′*cos ̂2(2*π/MP*x)+K′*sin ̂2(2*π/MP*x))=−I′*K′  (19)

Since the magnet units 25 a, 25 b are spaced from each other in the Y-axial direction by the distance L, the stage is driven by the thrusts exhibited by the formulae (18) and (19) with the use of respective different coils. These thrusts act upon the stage as a couple of forces, and accordingly, a moment θzm in the θz direction, acting upon the stage, is exhibited as follows:

θzm=I′*L*K′  (20)

That is, in order to induce a moment having a value Mz, a current value:

I′=θzm/LK′  (21)

is set in the formulae (14) to (17).

In order to control the position of the stage, the sum of the current value I for the thrust in the X-axial direction and the current value I′ for the thrust in the θz direction is fed as a current instruction value to the coils cx4, cx5, cx12 and cx13. Thus, the coils are used for both thrust in the X-axial direction and thrust in the θz direction, and accordingly, it is possible to reduce the provision of an additional current driver for a thrust in the θz direction.

In FIG. 4, current is fed to coils cy3 to cy16 in order to induce thrusts in the Y-axial direction and the θx direction. Since in the non-limiting example discussed no current is fed to coils cy1, cy18 located underneath the magnet units 25 a, 25 b, no forces are induced between the coils and the magnet units 25 a, 25 b. Further, in each of the magnet units 25 a, 25 b, four magnets can be arranged in a single row in the X-axial direction so that N-poles and S-poles are alternately opposed to the coil unit while a force induced by a magnetic flux from an N-pole magnet is set to be equal to that from an S-pole magnet. Thus, even though currents run through the coils cy1, cy18, the action of forces by these currents and the magnets in the θz magnet units can be cancelled out as internal forces, and accordingly, nothing is affected to a rigid-body motion applied to the stage. That is, the magnet units 25 a, 25 b are provided so that those coils which induce forces in the X-axial direction induce forces in the rotational direction around the Z-axis but those coils which induce forces in the Y-axial direction do not induce forces in the rotational direction around the Z-axis.

Such a case that the stage is displaced in the X-axial direction by one pitch CP so that its coordinate comes to x=CP, is analogous to such a condition that an (n+1)-th coil is located at the position of an N-th coil at x=0. Thus, by iterating the drive manner which has been explained hereinabove with periods of the coil pitches CP and CPY, a desired thrust can be induced at an arbitrary stage position. In this exemplary embodiment, although the magnet units 25 a, 25 b are arranged so as to interpose the magnet unit 24 therebetween in the Y-axial direction, there can also used such a configuration that a single magnet unit 25 can be arranged on one side of the magnet unit 24. In this configuration, the moment θzm in the θz direction induced in the stage is exhibited as follows;

θzm=0.5*I′*L*K′  (22)

It is noted that the formula 22 can be satisfied if the gravitational center of the stage is located at the center of the stage. If the gravitational center position of the stage is deviated from the stage center, it is sufficient to add the deviation as a correction value in the moment calculation. Further, in the case of an arrangement of the magnet unit only on one side, since only one of the formulae (18) and (19) gives a thrust, no couple of forces are induced so that a thrust is induced in the X-axial direction by a current for inducing a thrust in the θz direction. Such a thrust can be managed by a current value for inducing a thrust in the X-axial direction.

The magnet units 25 a, 25 b can be arranged on the left and right sides of the center line A as shown in FIG. 2, and further, they can be arranged to be left-right symmetric. Further, if a large moment force is desired, plural pairs of magnet units (e.g., 25 a and 25 b) can be provided, rather than one pair.

With the use of the stage configuration according to at least one exemplary embodiment, since the coils are used for both drive in a horizontal direction and drive in the θz direction, it is possible to reduce the provision of an additional current driver for the drive in the θz direction. Thus, the stage can be small-sized, and accordingly, an exposure device can be also small-sized as a whole. Further, in order to induce thrusts in the X-, Y- and Z-axial directions and the θx and θy directions, the magnets in the Halbach array can be tightly laid in a square shape with no missing, thereby it is possible to enhance the efficiency for inducing the thrusts.

It is noted that although the thrust in the θz direction is induced in the stage by the first coil layer, according to at least one exemplary embodiment, the thrust in the θz direction can be induced by the second coil layer. In this case, the magnet units 25 a, 25 b are arranged so as to interpose therebetween the magnet unit 24 in the X-axial direction.

(Example of an Exposure Device)

Referring to FIG. 5 which illustrates an exposure device for manufacturing a semiconductor device using a stage unit similar to that mentioned above, as a wafer stage. The exposure device can be used for manufacturing a device formed from a fine pattern, for example, a semiconductor device (e.g., a semiconductor integrated circuit, a micro machine, a thin film magnetic head, other pattern formed devices both macro, micro, and nano in size as known by one of ordinary skill in the relevant art and equivalents). An exposure beam (e.g., a visible light beam, an ultraviolet beam, an EUV beam, an X-ray radiation, an electron beam and other exposure beams as known by one of ordinary skill in the relevant arts and equivalents) from an illumination system unit 101, irradiates, after passing through a reticle with an original pattern and via a projection lens 103 (e.g., a refractive lens, a reflection lens, a catadioptric lens system, a charged particle lens and other projection lens systems as known by one of ordinary skill in the relevant arts and equivalents), a semiconductor wafer (substrate) forming a pattern of the original on the substrate, which can be mounted on the wafer stage 104. Further, in such an exposure device, as the wavelength of the exposure beam becomes shorter, exposure has been carried out more in a vacuum environment. A wafer (an object to be irradiated) as a substrate is held on a chuck installed on the wafer stage 104, and a reticle containing an original (i.e., an original pattern) to be exposed is mounted on a reticle stage 102 and is illuminated to transferred onto one of zones on the wafer in a step-and-repeat mode or a step-and-scan mode by the illumination system unit 101. It is noted here that the above-mentioned movement of the stage in exemplary embodiments can be used to move the wafer stage 104 or the reticle stage 102.

(An Example of a Method of Manufacturing a Device)

Next, explanation will be made of a process of manufacturing a semiconductor device with the use of the above-mentioned exposure device illustrated in FIG. 5. FIG. 6 is a view illustrating a flow-chart for explaining a process of manufacturing a semiconductor device. At step 1 (S1) (circuit design), a circuit design for a semiconductor device is carried out. At step 2 (S2) (manufacture of a mask), a mask is formed in accordance with the designed circuit pattern.

Meanwhile, at step 3 (S3) (manufacture of a wafer), a wafer is manufactured with the use of a material (e.g., silicon). Step 4 (S4) (wafer process) as the so-called preprocess, an actual circuit is formed on the wafer with the use of the mask and the wafer as mentioned above (e.g., by using lithography technology using the above-mentioned exposure device). The next step 5 (S5) (assembly) is the so-called post-process, a semiconductor chip is obtained with the use of the wafer manufactured by the step 4 (S4), this step 5 (S5) can include an assembling step which can include an assembly step (dicing, bonding), and a package step (chip enclosure). At step 6 (S6) (inspection), an inspection including an operation confirming test, and a duration test is carried out for the semiconductor device manufactured at step 5 (S5). Through the above-mentioned steps, the semiconductor device is completed. Thus, at step 7 (S7), the semiconductor device is delivered.

The wafer process at the above-mentioned step 4 (S4) can include the following steps (FIG. 7): a CVD step (S12) of forming an insulation film on the outer surface of the wafer, an electrode forming step (S13) of forming electrodes on the wafer by vapor deposition, an ion implantation step (S14) of implanting ions in the wafer and subsequent oxidation (S11), a resist process step (S15) of coating a photo-sensitive material on the wafer, an exposure step (S16) of transferring a circuit pattern by the exposure device onto the wafer after the resist process step, a developing step (S17) of developing the wafer exposed at the exposure step, an etching step (S18) of grinding a part other than the resist image developed at the developing step, and a resist peel-off step (S19) of removing the resist after the etching. With the repetitions of the above-mentioned steps, circuit pattern in multi-layers are formed on the wafer.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. 

1. A positioning apparatus, including a movable member having a plurality of magnets, and a plurality of coils which are arranged in X- and Y-axial directions, for moving the movable member in at least the X- and Y-axial direction, the positioning apparatus, comprising: a first magnet unit including a plurality of magnets arranged two-dimensionally, and exhibiting a periodic magnetic flux density distribution; and at least two second magnet units each including a plurality of magnets arranged one-dimensionally, and exhibiting a periodic magnetic flux density distribution, wherein two of the at least two second magnet units are arranged on opposite sides of the first magnet unit from each other.
 2. A positioning apparatus according to claim 1, wherein a first coil unit includes a plurality of coils which are arranged in the X-axial direction and which have a long length in the Y-axial direction, and a second coil unit includes a plurality of coils which are arranged in the Y-axial direction and which have a long length in the X-axial direction.
 3. A positioning apparatus according to claim 1, comprising: a first coil unit including a plurality of coils which are long in the Y-axial direction and which are arranged in the X-axial direction; and a second coil unit including a plurality of coils which are long in the X-axial direction and which are arranged in the Y-axial direction, wherein the second magnet unit is configured to generate a force in a rotational direction around a Z-axis between itself and either one of the first and second coil units.
 4. An exposure device for exposing a pattern onto a substrate, wherein the substrate is positioned with the use of a positioning apparatus according to claim
 1. 5. A device manufacturing method comprising the steps of: exposing a wafer with the use of the exposure device according to claim 4; and developing the wafer. 